1. Field of the Invention
The present invention relates to tractor trailer king pins and more particularly, to an improved locking arrangement for locking the king pin of a trailer. More particularly, the present invention relates to a locking apparatus for locking a fifth wheel king pin wherein a body envelops a king pin and a locking member to protect it, the body having a laterally extending passageway that is fully occupied by a locking member that engages annular shoulder portions of the king pin.
2. General Background of the Invention
King pins are provided on large trailers that are used to transport goods cross country on local, national and interstate highways. One of the most serious problems facing the owners and operators of such tractor trailer rigs is theft of the trailer and all of its contents. These trailers may often be filled with hundreds of thousands of dollars worth of goods that are subject to theft when left unattended, whether in a yard or enroute during a driver break.
In order to combat the problem of theft of large trailers, king pin locking devices and security devices have been developed and many patented in an attempt to combat thievery.
An early patent issued to Gallagher is entitled "Lock for Fifth Wheel King Pins". The Gallagher U.S. Pat. No. 2,641,124 affixes to a king pin that is generally cylindrical in form and which has an annular groove adapted to receive the usual fifth wheel of a tractor or other type of propelling means for the trailer. The Gallagher device includes a shroud that covers the king pin in the form of a sleeve that has a front casing welded thereto and extending tangentially therefrom. This arrangement is objectionable because it has exposed lock parts that could give a thief access to the lock by providing the projecting portion of the lock that could be hammered or smashed or cut with a powered saw or torch.
The Eble U.S. Pat. No. 3,415,085 provides a lock for a truck trailer. The device purportedly prevents the theft of tractor trailers, the device having a shroud for covering the grooved king pin of such trailers and a locking member for detachably securing the shroud around the king pin. As with the Gallagher patent, the Eble device provides projecting parts that could be hammered or cut.
Another such locking device for king pins is seen in the Gerlach U.S. Pat. No. 3,832,872, entitled "Trailer Coupling Pin Lock Collar". The Gerlach patent disclosed a cylindrical collar that is received upwardly telescoped over a downwardly projecting trailer coupling pin and a U-shaped keeper which is slidably received through the collar movable between pin engaging and disengaging positions. In the keeper pin engaging position, leg portions thereof span opposite portions of the collar opening passing through opposite portions of the usual annular recess of the coupling pin thereby retaining the collar over the coupling pin preventing the coupling pin from engaging a trailer pulling tractor. A lock through a pivotal cam bar slides a locking bar transversely into engagement with the keeper when the keeper is in its pin engaging position thereby locking the keeper in such pin engaging position. In the Gerlach device, exposed parts extend beyond the locking device so that they could be hammered or cut in order to gain access to the king pin.
The Mickelson U.S. Pat. No. 4,620,718, provides a king pin lock that relates to equipment for securing a truck trailer. The device employs a lock housing or body which has a hole which is adapted to fit over the trailer king pin. The device employs a lock housing or body which has a hole which is adapted to fit over the trailer king pin. A sliding member is employed to go into sliding contact with the groove in a standard trailer king pin. The sliding member is configured with a concave edge on one end in order to contact the annular groove in the standard trailer king pin. A slot in the sliding member is used to engage the body of a heavy duty padlock when in the locked position thus holding the sliding member in contact with the trailer king pin. A retaining means such as a screw threadably secured to the lock body and a mating slot in said sliding member is employed to prevent the inadvertent removal of said sliding member from the lock body. Exposed parts are present on the Mickelson device that could be hammered or cut in order to tear the device apart.
The Van Cuyk U.S. Pat. No. 5,052,203, provides a lock apparatus for use with a fifth wheel plate having a king pin characterized by an annular groove including a generally cylindrical cup adapted to enclose the king pin, the cup having a transversely extending slot which is registerable with the annular groove, bar means connected to the cup for selective registry with the slot and engagement with the groove, and locking means for locking the bar means into engagement with the groove.
The Richardson U.S. Pat. No. 5,136,863, discloses an anti-theft trailer pin lock. The Richardson device includes an inner member and an outer member to enclose a trailer king pin. The inner member has an outer shell with a laterally extending slot for receiving the king pin. Plates are mounted transversely of the shell adjacent to the slot edges for preventing axial movement of the inner member relative to the king pin. Padlock shackles are fixedly mounted to and extend radially from the inner member. A padlock body has a key cylinder for locking the padlock body onto the shackles. An outer sleeve member has an open end for receiving the inner member and shaft end, and a side opening positioned and sized to receive the padlock body during locking of the padlock body onto the shackles. The padlock body extends through the side opening when the padlock body is locked onto the shackles, whereby the inner member is fixed axially relative to the outer member and the shaft end is captured in the device.
A king pin security device is provided in U.S. Pat. No. 5,259,223. The apparatus includes a semi-circular plate transverse to a flat base. The pate has a channel therein, also preferably being semi-circular in cross-section. The channel in the plate defines a shoulder there above. The dimensions of the channel and the shoulder are such as to form a close fit with the annular recess and annular lip found on a standard king pin. Opposite the vertically extending plate, the base transitions to a longitudinally extending arm. At the distal end of the arm is a shield plate, disposed generally transverse and spaced apart from the base. After the king pin security device is affixed to a king pin, a standard padlock can be attached to this extending arm. The shackle of the padlock prevents disengagement of the king pin from the king pin security device. The shield plate prevents the padlock from slipping off the arm, as well as shielding it from vandals or intruders. The king pin security device also includes a downwardly extending vertical flange. This flange also serves to protect the body and shackles of the padlock.
U.S. Pat. No. 5,297,407 provides a collar member arranged to receive a trailer pin to effect surrounding of the trailer pin in order to prevent access to the trailer pin for unauthorized removal of the associated trailer structure. To this end, the collar includes a channel having a floor, and the channel further including a U-shaped rib arranged to guide a locking head onto the rib to secure the locking head within the channel and effect surrounding of the collar preventing access thereto.
These above prior art devices all suffer common inadequacies because they have exposed parts that extend beyond the main structural body of the lock. Such exposed parts can be hammered, cut, pried or burned in order to defeat the lock.
The present invention is an improvement to these prior art devices by providing a locked member that does not expose any parts beyond the outer surface of the lock body. The lock body is further formed of a specially toughened, treated material which is resistant to normal steel cutting instruments such as powered saws and welding/cutting torches. This provides a very rugged, structurally sound locking mechanism that is not easily dismantled by a thief.